It seems that a lot of drug-related money is being moved with these cards and the government is looking at them more closely. I would imagine you can expect some legislation regarding them soon.
http://news.yahoo.com/s/ap/20110523/...ney_laundering
"...The Treasury wants to require any business selling cards that can be used internationally to keep customer identity records and report suspicious transactions. That would affect more than 43,000 U.S. sellers including mom-and-pop groceries and stores such as Wal-Mart..."
c.a.